1. Field
The technical field is related to a display device, e.g., an organic light emitting display device.
2. Description of the Related Art
Various display devices have been widely used in electronic devices. Display devices may include liquid crystal display (LCD) devices and organic light emitting display (OLED) devices.
A display device, such as an OLED device, may include a substantially transparent region for showing an object (or a target) that is located in the rear (e.g., the back) of the display device. The display device may also include a pixel region that can emit light for displaying an image. Multiple insulation layers may be disposed in both the transparent region and the pixel region. Refractive indexes of the insulation layers may be substantially different from each other. Therefore, transmissivity of the transparent region may be unsatisfactory. In addition, color characteristics associated with a light transmitted via the transparent region may be undesirably changed. One or more of the insulation layers may be based on nitride, may directly contact an active layer of the display device, and may negatively affect electron mobility of the active layer, such that performance of the display device may be unsatisfactory.